بررسي عددي جريان و انتقال حرارت جابجايي تركيبي نانوسيال نيوتني و غيرنيوتي در محفظه مربعي باز حاوي چشمه حرارتي

Numerical Investigation of Heat and Fluid Flow in an Open Square Cavity with Nanofluids Newtonian & non Newtonian

در تحقيق حاضر انتقال حرارت جابجايي تركيبي نانوسيال نيوتني و غير نيوتني در يك محفظه در حال تهويه با حضور مانع داخلي به صورت دوفازي مورد برسي قرارگرفته است و نانو سيالات آب- اكسيد آلومنيوم و آب- اكسيد مس به عنوان سيال عامل در نظر گرفته شده است. معادلات حاكم با استفاده از روش عددي حجم محدود گسسته سازي و با استفاده از روش دوفازي اويلري- اويلري حل شده اند. در اين پژوهش چشمه حرارتي داراي شارحرارتي ثابت وتمام ديواره هاي محفظه از نظر حرارتي نيز عايق مي باشند. نتايج حاصل از اين تحقيق نشان مي‌دهند كه در رينولدز 100 و گراشف 105، ناسلت متوسط با حضور نانو ذره اكسيد مس ،24/61 درصد نسبت به آب خالص افزايش و همچنين با افزايش كسرحجمي نانوذرات از0/02 به 0/05 ناسلت متوسط 2/11 درصد افزايش مي‌يابد.

In the present study, mixed convection heat transfer of two-phase Newtonian and non- Newtonian nanofluids was examined in a ventilated cavity with internal barrier. Water - Aluminum oxide and water - copper oxide nanofluids are considered as working fluid, and the governing equations are discrete using a finite volume numerical method and solved by the Eulerian-Eulerian two-phase method. In this research, heat source has a constant thermal flux and all cavity walls are also thermally insulated; Finally, the effect of parameters such as Grashof number, volumetric fraction of nanoparticles, Reynolds number, type of nanofluid and different locations of the heat source were considered and Aluminum oxide nanoparticle with an ethylene glycol based fluid, which is converted to Bingham-type non-Newtonian fluid, has also been investigated. The results of this study show that with a Reynolds No. of 100 and Grashof No. of 105, the average Nusselt was 24.61% higher than that of pure water at the presence of copper oxide nanoparticles, and also by increasing the volume fraction of nanoparticles from 0.02 to 0.05, average Nusselt increase by 2.11 percent, indicating that water-copper oxide nanofluid has a better heat transfer than pure water.